1. Field of the Invention
The present invention relates to an actuator structure mounted on various types of electronic devices to form a movable section of the device, and also relates to an actuator block and an electronic device using the structure.
2. Background Art
Recently, as penetration of camera-equipped mobile phones increases, the needs for compact and high-performance components, such as a lens module, have been growing.
As a conventional structure of a lens module, combination of a spring and a voice coil has generally been employed. FIG. 6 shows a conventional structure of a lens module.
According to a conventional lens module, as shown in the section view of FIG. 6, support frame 5 for fixing lens 6 is disposed in a gap between magnet 2 and yoke 3. At the lower end of support frame 5, voice coil 4 is disposed. In addition, spring 7 is located between support frame 5 and yoke 3. Lens module 1 is thus formed.
An electric current is applied to voice coil 4 to produce upward electromagnetic force. Lens 6 fixed by support frame 5 moves to a position at which the electromagnetic force and a restoration force of spring 7 balance with each other.
For example, Japanese Patent Unexamined Publication No. 2003-207708 is a well-known prior art that relates to the present invention.
In the conventional lens module above, however, the actuator structure, which is formed of magnet 2, yoke 3, and voice coil 4, is disposed over the circumference of the cylindrical shape of the lens module. The arrangement has inevitably invited a bulky shape of the entire module, and accordingly, has required a device on which the module is mounted to have an area wide enough for accepting the module.